Meet Michael Decker, musical investigator.

He already has a sterling reputation as a classical guitarist, not to mention mandolin, banjo and bouzouki player. He often performs with the Baltimore and National symphony orchestras - he's playing the banjo today with the BSO for its live film-score accompaniment to Charlie Chaplin's City Lights. And he has played in the pit bands for dozens of Broadway shows. Now, this 30-year veteran of Towson University's music faculty has revealed a new talent: reclaiming the past.

He already has a sterling reputation as a classical guitarist, not to mention mandolin, banjo and bouzouki player. He often performs with the Baltimore and National symphony orchestras - he's playing the banjo today with the BSO for its live film-score accompaniment to Charlie Chaplin's City Lights. And he has played in the pit bands for dozens of Broadway shows.

Now, this 30-year veteran of Towson University's music faculty has revealed a new talent: reclaiming the past.

After a painstaking excavation and reconstruction effort, Decker, 56, is about to realize a long-held dream of performing the 1986 Concerto for Classical Guitar and Jazz Orchestra by the British composer Paul Hart, who played violin and piano for the jazz singer Cleo Laine.

Hart's 40-minute concerto, with two kinetic movements surrounding a Latin-infused ballad section, is prized by guitar aficionados because of a recording made in 1986 by the celebrated Australian classical guitarist John Williams with England's National Youth Jazz Orchestra. But the score was never published, so the concerto didn't really exist, for all practical purposes.

Decker, who studied at the Peabody Conservatory and is now coordinator of Towson's guitar and music industry programs, decided to change that.

During a sabbatical, he tracked down the remaining skeleton of the composition and fleshed it out fully, producing a fresh score. He'll give the American premiere of the concerto this week - the first performance anywhere in two decades - with the Towson University Jazz Orchestra. Where did the idea come from for this reclamation project, and what material did you have to start with?

I used to buy every new guitar recording that came out, and when I heard the Williams recording in 1986, my reaction was, 'Wow, who would have thought of putting a classical guitar and jazz orchestra together?' The orchestration was bigger than for the usual big band or swing band [five saxes, four trumpets, four trombones and rhythm section of piano, guitar, bass and drums]. Hart added flute, piccolo, French horn, vibraphone, synthesizer, Latin percussion and extra trumpets. It requires 34 players.

I played the recording for Glenn Cashman [then head of Towson's jazz/commercial music division], and he said, 'Oh my God, we've got to do this.' Then I spent 20 years doing nothing, essentially, because I couldn't find a publisher of the concerto. I called Sony, which made the Williams recording, and they couldn't offer any help. The CD went out of print.

About 18 months ago, I was doing a random search online and found a publisher of works played by the National Youth Jazz Orchestra. I saw the name Bill Ashton, who had been involved in the 1986 recording. I contacted him and he told me he owned the rights, and he had the original manuscript. But he said that Hart had continued to make revisions and add parts during the recording sessions, and there was no score that included all of those additions. The manuscript had never been edited for publication. There also were no [individual instrument] parts. When Ashton sent you a photocopy of the manuscript, how did you go about the task of producing a new score?

The first thing I needed was new computer equipment. Our computers here at the university aren't fast enough and don't have the memory you need. I used a program called Sibelius, which is now the world's foremost music notation software. [Instead of writing notes by hand, the user inputs them with a computer keyboard.] It took three or four different strokes to get each note onto the score. The constant terror was that I might forget to save.

I knew the concerto well from the recording, but there were so many differences between that and the manuscript. There were tons of changes in the guitar part that had not been notated. There was a lot of shorthand in the manuscript, and some inconsistencies. I would listen over and over - I hate to think how often - to the CD to try to hear the things that changed from the manuscript. I would think I had everything down, and then discover little changes that I didn't catch at the first listen. And I couldn't always be sure of what I was hearing in some of the instruments. I relied on my faculty colleagues, asking them to listen and help me figure out the notation.

I started in November 2006. I finished inputting in July '07, then took another three months for editing. We computed the hours I spent just getting all the notes down: 600. It would have cost $34,000 to pay a professional copyist to prepare it. And if you paid that much to produce a score that you could publish, you would never recover that cost in rentals, not in a lifetime. The full score ended up being 414 pages; the set of all the individual parts is over 1,000 pages. What do you find particularly appealing about the concerto?

The most thrilling thing for me is the use of three groups of trumpets, two of them placed in the rear corners of the hall to deliver a phenomenal blast of sound for the finale. Part of what makes the concerto so exciting on the recording is that it has a real edge; it's very fast. For our performance, we've pulled the tempos back in the fast movements. Slowing it down a little will enable the audience to hear the music better. But it's still an exciting ride, a wild roller coaster. The last movement, "Plymouth Hoe-Down," is pretty diabolical. But in the second movement, "Ballad," and in interludes between movements, the guitar can play more romantically. I know that most classical guitarists use a microphone and subtle amplification, because the instrument can be hard to hear otherwise in a concert hall. But, even with some electronic help, pitting the subtle, acoustic classical guitar against a big jazz orchestra doesn't seem like a fair fight. How do you solve the practical problem of achieving the right balance, so the guitar can be heard?

I would be the first to admit that I didn't anticipate the extent of that. For the recording, the guitar was recorded separately in a sound booth. Our plan is to have me to the side of the stage, rather than in front of the orchestra, surrounded by an acoustical shell, so the mike doesn't pick up the orchestra. But when you put a mike on a guitar, you can hear every shuffle, so turning the mike up real loud is still a problem. You run into a situation where you hear too much of the mechanics of making the instrument make a sound. Could the concerto be played by an electric guitar?

There are flamenco-like things in the score, and they just wouldn't sound right on an electric guitar. And although it would be easier to play some of the "Ballad" music on an electric guitar, you would miss the quality of the classical guitar's timbre. But an electric guitar could be the answer to the balance problem. Where did your own love of the guitar begin?

When I first played the guitar, it was because of The Beatles. I wanted to be a rock guitarist. I grew out of that and moved into jazz. Then I got into classical guitar. Baltimore is the most important classical guitar city in the country because of Peabody and people like [faculty member] Manuel Barrueco, who many think of as the greatest living classical guitarist. Will Paul Hart be here to witness the rebirth of his concerto this week?

We didn't try to invite him. We would be too embarrassed to say that we couldn't afford to bring him here from London.

tim.smith@baltsun.com

>>>If you go Concerto for Classical Guitar and Jazz Orchestra will be performed at 8:15 p.m. Wednesday at Towson University's Center for the Arts, Osler and Cross Campus drives. Tickets are $7 and $13. Call 410-704-2787 or go to towson.edu/centerforthearts.